Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op

From	Pavel Machek <pavel@ucw.cz>
Newsgroups	linux.kernel
Subject	Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op
Date	2015-08-19 21:40 +0200
Message-ID	<pZhnk-713-9@gated-at.bofh.it> (permalink)
References	(1 earlier) <pWevF-1vq-27@gated-at.bofh.it> <pX1G2-5TR-13@gated-at.bofh.it> <pXi4b-4fw-25@gated-at.bofh.it> <pZcdY-88J-17@gated-at.bofh.it> <pZcnD-8k5-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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> > >There are around 60 drivers in the other kernel subsystems that register
> > >LED class devices. If we chose the way you proposed then we would have
> > >to adjust all of them to the LED core changes, which could complicate
> > >the situation during merge window if there were other modifications in
> > >the affected drivers.
> 
> You don't need to change anything, if the semantics of
> brightness_set() does not change. All current drivers don't
> sleep. They use a work queue if needed to ensure they don't
> sleep. Hence they are correct.

Exactly. As you explain above, there are 60 reasons not to change
existing semantics.

> By adding a new operation, brightness_set_blocking(), you can strip
> out this work queue and move to the new op member one driver at a
> time. And you can take as long as you want doing this. No flag day
> when an API suddenly means something totally different.

Yes please.

									Pavel
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[PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op Jacek Anaszewski <j.anaszewski@samsung.com> - 2015-08-11 12:00 +0200
  Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op Pavel Machek <pavel@ucw.cz> - 2015-08-13 16:30 +0200
  Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op Andrew Lunn <andrew@lunn.ch> - 2015-08-13 16:30 +0200
    Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op Jacek Anaszewski <j.anaszewski@samsung.com> - 2015-08-14 10:00 +0200
      Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op Jacek Anaszewski <j.anaszewski@samsung.com> - 2015-08-19 16:10 +0200
        Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op Andrew Lunn <andrew@lunn.ch> - 2015-08-19 16:20 +0200
          Re: [PATCH/RFC v5 01/57] leds: Add brightness_set_nonblocking op Pavel Machek <pavel@ucw.cz> - 2015-08-19 21:40 +0200

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